Abrasive cutting surgical instrument

ABSTRACT

Surgical tools for removal of tissue, namely instruments, devices and methods for surgical tissue cutting with a cylindrical cutting burr bit extending from an elongated hollow member and connected to a shaft for actuating rotation motion of said burr bit to cut/remove tissue from a target location, while mitigating the harm of damaging surrounding tissue.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.15/205,854 filed on Jul. 8, 2016 which claims the benefit of andpriority to U.S. Provisional Application No. 62/190,261 filed Jul. 9,2015. The contents of the above applications are all incorporated byreference as if fully set forth herein in their entirety.

TECHNICAL FIELD

The present disclosure generally relates to the field of surgical toolsfor removal of tissue.

BACKGROUND

Excess body tissue can lead to pathological conditions and pain,especially when the excess tissue affects the nervous system. One commonproblem is the excess of bone tissue affecting the spinal cord, whichcauses Spinal Stenosis. Two of the most prominent conditions associatedwith excess bone growth are narrowing (stenosis) of the spinal canalresulting in a neurological deficit, and bulging or herniated disc,which are associated with osteophyte formation in the spinal canal.

A common treatment of Spinal Stenosis is a surgical procedure calledcorpectomy, which involves removing from all or part of the vertebralbody any bone spurs pushing into the spinal cord, usually as a way todecompress the spinal cord and nerves to alleviate or treat theneurological deficit. As to a herniated disc, it is commonly treatedwith a surgical procedure called discectomy, during which herniated discmaterial that presses against the nerve root or spinal cord is removed.

These surgical procedures, and others, require a selective removal ofcertain tissue while not harming surrounding tissue that can be fragileor vulnerable to damage with harmful consequences, wherein the undesiredtissue intended for removal can be located in positions that aredifficult to reach. Additionally, the tissue that is intended forremoval is commonly hard tissue such as bone, which requires specialphysical properties from the grinder.

There is thus a need in the art for surgical instruments that providesselective cutting of tissue in difficult locations, while mitigating theharm of damaging surrounding tissue

SUMMARY

The following embodiments and aspects thereof are described andillustrated in conjunction with systems, tools and methods which aremeant to be exemplary and illustrative, not limiting in scope. Invarious embodiments, one or more of the above-described problems havebeen reduced or eliminated, while other embodiments are directed toother advantages or improvements.

US Publication No. US20150342619, to the inventor of the presentinvention published after the priority date of the current application,discloses a flexible drive shaft for use in bone removal. The teachingsof US20150342619 are incorporated herein in their entirety by reference.

The incorporation particularly includes the following:

“[0090] According to still further features in some describedembodiments the drive shaft includes a multi-layer wire cable configuredfor high torsional rigidity and low bending rigidity.

[0091] According to still further features in some described embodimentsthe multi-layer wire cable includes: (i) inner layers configured formaintaining high structural integrity and (ii) outer layers configuredfor maintaining high torsional rigidity (iii) each layer may beconfigured to have mechanical properties in a direction opposite to thedirection of the adjacent layer.

[0092] According to still further features in some described embodimentsthe multi-layer wire cable may be capable of supporting an optionallybidirectional rotational speed of up to, for example, 40,000 rpm and atorque of up to, for example, 5 Ncm.

[0093] According to still further features in some described embodimentsa proximal end of the elongated device body includes a seal for sealingthe irrigation lumen, even over a shaft rotating at high speed.

[0094] According to still further features in some described embodimentsthe seal may be composed of a temperature resistant material having aShore durometer value of, for example, 50 A or less.

[0095] According to still further features in some described embodimentsthe temperature resistant material may be silicon rubber,self-lubricating silicon rubber or self-lubricating silicon rubberincluding silicon oil having a temperature independent viscosity.

[0096] According to still further features in some described embodimentsa proximal end of the elongated device body includes a mechanism forforcing flow of fluid within the irrigation fluid under rotation of thedrive shaft.

[0097] According to still further features in some described embodimentsthe drive shaft includes a tube crimped over the multi-layer wirecable.”

and

“[0148] Some embodiments of the device of the present invention includean elongated device body having a curved distal portion. A portion ofthe elongated device body is also termed herein a shaft, or an elongatedshaft, or an elongated shaft body.

[0149] As is further described herein, the elongated device body and itscurved distal portion potentially enable accurate positioning of thecutting head against an internal surface of a lamina and/or a tissueimpinging on a nerve fiber.

[0150] The elongated device body may be, for example, 30-250 mm inlength (e.g. 104 mm) with the curved distal portion being, for example,49-269 mm in length (e.g. either 123 mm or 116 mm depending on use) andhaving a radius of curvature, for example, of 4-12 mm (e.g. 9 mm). Sucha radius of curvature forms an angle between the curved portion and thestraight portion of elongated device body of, for example, 90-160degrees, e.g. 105 and 135 degrees (model dependent).

[0151] The elongated device body optionally has a circular or oval crosssection with an external diameter of, for example, 2-5 mm, e.g. 3.2 mm.The diameter and/or cross sectional shape of the elongated device bodymay be constant along its length or may vary, for example, from a largerdiameter at a proximal end to a smaller diameter at a distal end or viceversa.

[0152] The elongated device body may be fabricated from any materialused in surgical devices, including, for example, stainless-steel,titanium, a polymer and the like. The various device components may befabricated using well known approaches such as casting, extrusion,machining and the like.

[0153] In some embodiments, the elongated device body includes at leastone lumen which extends from a proximal end of the device body to acutting head which may be attached to a distal end of the elongateddevice body. The lumen optionally follows the curvature of the elongateddevice body and has a diameter of, for example, 1-4 mm (e.g. 2.8 mm)which may be configured for intimately housing a drive shaft (forexample, 30-100% larger than the flexible drive shaft diameter) toensure that at least a flexible portion of the drive shaft does not kinkor warp within the lumen. The lumen for containing the drive shaft isoptionally centered within the elongated device body. The drive shaftextends from a motor optionally positioned within a handle optionallyattached to the proximal end of the device body to the cutting head andoptionally transmits rotational (optionally bidirectional) andoptionally forward/backward motion to the cutting head. The drive shaftmay optionally include a substantially rigid portion connected to(mechanically, via crimping, or via welding), or contiguous with asubstantially flexible portion. The rigid portion optionally traversesat least some of the straight portion of the elongated device body,while the flexible portion traverses the curved portion, and optionallysome of the straight portion. As is further described herein, the driveshaft may include a rigid tube crimped over an end of a flexiblemulti-layer cable.

[0154] The multi-layer wire cable may be configured for high torsionalrigidity and low bending rigidity, potentially enabling the wire cableto rotate at high speed while bent, potentially at a small radius ofcurvature. The high torsional rigidity and low bending rigidity isbeneficial for service in a bent form. Having a low bending rigiditypotentially allows for low bending-related stress and better resistanceto fatigue potentially caused by high rotation speed and/or highrotation torque. Such a wire cable may be braided, coiled or twistedfrom inner layers configured for maintaining high structural integrity,and optionally low torsional rigidity, and outer layers configured formaintaining high torsional rigidity. The multi-layer wire cable includesat least one inner layer, optionally more, and at least one outer layer,optionally more. In order to further enhance the ability of the cable totransmit torque to the cutting head without fraying and/or bucklingand/or breaking, each of the above layers may be configured to havemechanical properties in a direction opposite to the direction of theadjacent layer. It is noted that a typical mode of failure of themulti-layer wire cable, especially when operating as part of the tissueremoval device, is that the strands are eventually broken or cut. Themode of failure is typically a dynamic failure.

[0155] The wire cable core may be fabricated, for example, from seven304V stainless-still wires (each having a diameter of, for example,0.084 mm) twisted into a rope. Several layers of coils, e.g. 3 layers,are then wound around the rope core. Each successive coil may optionallybe wound in the opposite direction of the coil which precedes it. Theinner coil (closest to rope core) includes, for example, five wires(with a diameter of e.g. 0.12 mm each), the middle coil includes, forexample, five wires (with a diameter of e.g. 0.14 mm each) and the outercoil includes, for example, five wires (with a diameter of e.g. 0.16 mmeach).

[0156] The cable design is capable of transferring rotational andlongitudinal motion, i.e. torque and rotational speed and axial forceand speed, along a curved path with angles described elsewhere herein,in a manner resistant to fatigue. It is noted, however, that such pathscan be fixed, as in some embodiments where the curved tip may be rigid,or variable, where the tip can accept multiple angles or curvaturesbefore and/or during the tissue cutting, as in the prior patentapplication by the same inventor, PCT Published patent application WO2012/004766.

[0157] In some embodiments the flexible drive shaft, such as, forexample, the wire cable described above, has a diameter of, for example,0.3 mm to 5 mm, e.g. 0.5 mm or 1.5 mm or 3 mm.”

In surgical procedures for removal of excess tissue, it is of highimportance to perform selective removal only of the undesired tissue,while mitigating any removal or damage of surrounding tissue.

According to some embodiments, there are provided devices, systems andmethods for selective tissue removal including a burr bit, mechanicallyconnected to a rotary shaft, and partially covered by a protectiveshield; the burr bit being configured to remove/cut tissue by impactingthe tissue during rotation.

According to some embodiments, the protective shield is configured toseparate between the burr bit and tissue, thereby mitigating the risk ofimpacting the tissue by rotation of the burr bit. According to someembodiments, the protective shield is configured to mechanicallyseparate between two tissue layers to facilitate introduction of theburr bit to target tissue.

A common challenge in surgeries for tissue removal is the ability toreach the target tissue for removal.

According to some embodiments, the shaft is bendable and is locatedwithin a bendable hollow member for facilitating positioning the burrbit in a close proximity to the target tissue. According to someembodiments, the shaft and surrounding hollow member are bendable suchthat a distance between the burr bit and the bending location is lessthan 10 mm, advantageously facilitating reaching to desired targettissue.

Applying rotation motion on a drive shaft, especially when the shaft isbent and impact of tissue is applied, may cause damage to the shaft.According to some embodiments, the shaft is made of stranded wires,structured to have certain bendability and strain tolerance properties.According to some embodiments, the strained wires shaft is a multi-layerstranded wire shaft, in which at least some layers of stranded wireshave a clockwise stranding while other layers have a counter clockwisestranding.

According to some embodiments, the burr bit is cylindrical, and therotation thereof is done along the cylinder central axes.Advantageously, a cylindrical burr may facilitate a large surface ofimpact for cutting the target tissue. According to some embodiments, thelarge surface of impact is advantageous in achieving high durability ofthe burr, as the impact with the tissue is dispersed over a large areaon the burr. According to some embodiments, the large surface of impactwith the tissue may facilitate effective operation of tissue cutting byreduction of operation time.

When operating the cutting tip, the rotating burr impacts the targettissue, causing undesired movements of the burr which may reduce theeffectiveness of the cutting operation, as well as damage the tip.According to some embodiments, the tip includes a bearing, configured tosupport the burr bit in a desired position relative to the tip, whilefacilitating low friction rotation movement of the burr tip foroperation.

According to some embodiments, there is provided a surgical tissuecutting tip, including an elongated hollow member, having a distal openend, a burr bit, distally protruding from the distal open end of saidhollow member, the burr bit comprising, a proximal bit end, configuredto be mechanically connected to a target end of a rotary shaft, acylindrical burr body having circumferential cutting/abrasivecharacteristics, and a distal bit front end, and a burr shield extendingfrom the distal open end of said hollow member to at least partiallycover the cylindrical burr body and at least partially cover said distalbit front end, wherein said burr bit is configured to rotate axially inan axis extending from said proximal bit end to said distal bit frontend, and to affect abrasive grinding/cutting of tissue by contact withsaid burr body at areas not covered by said burr shield. According tosome embodiments, the burr shield is integrally formed with the distalopen end of said hollow member. According to some embodiments, the burrshield is contiguous to the distal open end of said hollow member.According to some embodiments, the burr shield is attached to (forexample, removably attached to) the distal open end of said hollowmember.

According to some embodiments, the tip further includes a rotary shaft,configured to be placed within said elongated hollow member, the rotaryshaft having a driving end configured to be mechanically connected to arotary motion actuator, a target end, positioned near said distal openend of said hollow member and configured to be mechanically connectedwith said proximal bit end to affect rotary motion to said burr bit, andan elongated shaft body configured to provide/transfer rotationalmovement from a said driving end to said target end. According to someembodiments, said burr shield is configured to cover a lower section ofsaid burr bit and is extended upwardly to at least partially cover saiddistal bit front end. According to some embodiments, said burr shield isconfigured to facilitate separation between a hard tissue intended forcutting and a soft tissue.

According to some embodiments, the tip further includes a middle bearingelement placed by said distal open end of said hollow member, andconfigure to support said proximal bit end to reducing lateral radialmovement thereof, while facilitating axial rotation of said burr bit.According to some embodiments, the tip further includes a distal bearingelement, integrated in said burr shield in proximity to said distal bitfront end, configured to facilitate rotation of said burr bit. Accordingto some embodiments, said distal bit front end is dome-shaped. Accordingto some embodiments, said tip has a length to radius ratio in the rangeof about 0.5-2. According to some embodiments, said tip has a length ofabout 9 mm, and a radius of about 9 mm.

According to some embodiments, said rotary shaft comprises a bent orbendable coiled and stranded wires, and said hollow member is bent orbendable at a bending location on the longitude thereof to facilitatepositioning said burr tip at desired positions. According to someembodiments, a distance between said bending location and said burr tipis less than 20 mm. According to some embodiments, the said rotary shaftand said hollow member are bent or bendable at a bending angle of up to90 deg. According to some embodiments, the said rotary shaft and saidhollow member are bent or bendable at a bending radius of less than 10mm.

According to some embodiments, there is provided a surgical tissuecutting tool, including an elongated hollow member, having a distal openend, a rotary shaft, configured to be placed within said elongatedhollow member, the rotary shaft including, a driving end configured tobe connected to a rotary motion actuator, a target end, positioned nearsaid distal open end of said hollow member and configured to affectrotary motion to a target object, and an elongated shaft memberconfigured to provide/transfer rotational movement from a said drivingend to said target end, a burr bit, protruding from the distal open endof the hollow member, the burr bit comprising, a proximal bit end,mechanically connected to said target end of said rotary shaft, acylindrical burr body having circumferential cutting elements, and adistal bit front end, and a burr shield extending from the distal openend of said hollow member to at least partially cover the cylindricalburr body and at least partially cover said distal bit front end,wherein said burr bit is configured to rotate axially in an axisextending from said proximal bit end to said distal bit front end, andto affect abrasive grinding/cutting to tissue coming in contact withsaid burr body at areas not covered by said burr shield.

According to some embodiments, the tool further includes a handleconfigured to facilitate operation and control of said device by anoperator. According to some embodiments, the tool further includes arotary actuator, placed within said handle configured to induce rotationmotion to said rotary shaft by said driving end thereof. According tosome embodiments, the tool further includes a control-interfaceconfigured to facilitate operation control over a rotation speed of saidrotary actuator, rotation intermittency, a rotation direction or bendingof said hollow member.

According to some embodiments, said burr shield is configured to coveran entire length of said burr bit and is extended upwardly to at leastpartially cover said distal bit front end.

According to some embodiments, the tool further includes a middlebearing element placed by said distal open end of said hollow membersurrounding said proximal bit end, configured to facilitate rotation ofsaid burr bit. According to some embodiments, the tool further includesa distal bearing element, integrated in said burr shield in proximity tosaid distal bit front end, configured to facilitate rotation of saidburr bit. According to some embodiments, said distal bit front end isdome-shaped. According to some embodiments, said shield is dome-shaped.

According to some embodiments, there is provided a method for surgicaltissue cutting, comprising introducing a surgical cutting tip having ahollow member with a distal open end, a cutting bit with a distal frontend and a cylindrical burr body having circumferential cuttingcharacteristics, and a shield extending from the distal open end of thehollow member to at least partially cover the cylindrical burr body andat least partially cover distal front end of the bit, approaching thecutting bit burr body to the vicinity or a target tissue, rotating thecutting bit axially, and introducing/impacting the burr body of therotating cutting bit with the target tissue to affect a cutting therein.

According to some embodiments, the method further includes separatingbetween a soft tissue and a hard tissue utilizing the shield. Accordingto some embodiments, the soft tissue is a ligament, and the hard tissueis a bone.

Certain embodiments of the present disclosure may include some, all, ornone of the above advantages. One or more technical advantages may bereadily apparent to those skilled in the art from the figures,descriptions and claims included herein. Moreover, while specificadvantages have been enumerated above, various embodiments may includeall, some or none of the enumerated advantages.

In addition to the exemplary aspects and embodiments described above,further aspects and embodiments will become apparent by reference to thefigures and by study of the following detailed descriptions.

BRIEF DESCRIPTION OF THE DRAWINGS

Examples illustrative of embodiments are described below with referenceto figures attached hereto. In the figures, identical structures,elements or parts that appear in more than one figure are generallylabeled with a same numeral in all the figures in which they appear.Alternatively, elements or parts that appear in more than one figure maybe labeled with different numerals in the different figures in whichthey appear. Dimensions of components and features shown in the figuresare generally chosen for convenience and clarity of presentation and arenot necessarily shown in scale. The figures are listed below.

FIG. 1 schematically illustrates a device for hard tissue removal with aforward shield for differentiating between hard and soft tissue,according to some embodiments;

FIG. 2a schematically illustrates a surgical tip with a forward shieldfor differentiating between hard and soft tissue, according to someembodiments;

FIG. 2b schematically illustrates a cross section of a surgical tip witha forward shield for differentiating between hard and soft tissue,according to some embodiments;

FIG. 3a schematically illustrates a side view of a bent surgical tipwith a forward shield for differentiating between hard and soft tissue,according to some embodiments;

FIG. 3b schematically illustrates a perspective view of a bent surgicaltip with a forward shield for differentiating between hard and softtissue, according to some embodiments;

FIG. 4a-f schematically illustrate steps of operating a surgical tip forhard tissue removal, according to some embodiments;

FIG. 5a schematically illustrates a surgical tip with a distal/front anda middle bearing, according to some embodiments;

FIG. 5b schematically illustrates a surgical tip with a cross section ofa distal/front and a middle bearing, according to some embodiments;

FIG. 6 schematically illustrates a cross section of a surgical tip witha distal/front bearing, according to some embodiments;

FIG. 7 schematically illustrates a surgical device with a handle, astraight elongated shaft body a cutting tip and a cutter, according tosome embodiments;

FIG. 8 schematically illustrates a cross section of a surgical devicewith a handle, a straight elongated shaft body a cutting tip and acutter, according to some embodiments;

FIG. 9a schematically illustrates a tissue cutting tip with a burr bitat a collapsed/retracted position, according to some embodiments;

FIG. 9b schematically illustrates a tissue cutting tip with a burr bitat an engaged/extended position, according to some embodiments;

FIG. 10a schematically illustrates a tissue cutting tip at a targetarea, according to some embodiments;

FIG. 10b schematically illustrates an enlarged view tissue cutting tipat a target area, according to some embodiments;

FIG. 11a schematically illustrates a tissue cutting tip with a bentshaft at a target area, according to some embodiments;

FIG. 11b schematically illustrates an enlarged view of a tissue cuttingtip with a bent shaft at a target area, according to some embodiments;

FIG. 12a schematically illustrates a tilted front view of a tissuecutting tip, according to some embodiments;

FIG. 12b schematically illustrates a side view of a tissue cutting tip,according to some embodiments;

FIG. 12c schematically illustrates a perspective view of a tissuecutting tip, according to some embodiments;

FIG. 13 schematically illustrates a technical design of a tissue cuttingtip, according to some embodiments;

FIG. 14 schematically illustrates a tissue cutting device with anelongated burr bit, according to some embodiments;

FIG. 15a schematically illustrates a tissue cutting tip with anelongated burr bit, according to some embodiments;

FIG. 15b schematically illustrates a cross section of a tissue cuttingtip with an elongated burr bit, according to some embodiments, and

FIG. 16 schematically illustrates an operation of a tissue cutting tipwith an elongated burr bit, according to some embodiments.

DETAILED DESCRIPTION

In the following description, various aspects of the disclosure will bedescribed. For the purpose of explanation, specific configurations anddetails are set forth in order to provide a thorough understanding ofthe different aspects of the disclosure. However, it will also beapparent to one skilled in the art that the disclosure may be practicedwithout specific details being presented herein. Furthermore, well-knownfeatures may be omitted or simplified in order not to obscure thedisclosure.

In surgical procedures for removal of excess tissue, it is of highimportance to perform selective removal only of the undesired tissue,while mitigating any removal of damage of surrounding tissue.

According to some embodiments, there are provided devices, systems andmethods for selective tissue removal including a burr bit, mechanicallyconnected to a rotary shaft, and partially covered by a protectiveshield; the burr bit being configured to remove/cut tissue by impactingthe tissue during rotation.

According to some embodiments, the protective shield is configured toseparate between the burr bit and tissue, thereby mitigating the risk ofimpacting the tissue by rotation of the burr bit. According to someembodiments, the protective shield is configured to mechanicallyseparate between two tissue layers to facilitate introduction of theburr bit to target tissue.

A common challenge in surgeries for tissue removal is the ability toreach the target tissue for removal.

According to some embodiments, the shaft is bendable and is locatedwithin a bendable hollow member for facilitating positioning the burrbit in a close proximity to the target tissue. According to someembodiments, the shaft and surrounding hollow member are bendable suchthat a distance between the burr bit and the bending location is lessthan 10 mm, advantageously facilitating reaching to desired targettissue.

Applying rotation motion on a drive shaft, especially when the shaft isbent and impact of tissue is applied, may cause damage to the shaft.According to some embodiments, the shaft is made of stranded and/orcoiled wires, structured to have certain bendability and straintolerance properties. According to some embodiments, the coiled wiresshaft is a multi-layer stranded wire shaft, in which at least somelayers of stranded wires have a clockwise coiling while other layershave a counter clockwise coiling.

According to some embodiments, the burr bit is cylindrical, and therotation thereof is done along the cylinder central axes.Advantageously, a cylindrical burr may facilitate a large surface ofimpact for cutting the target tissue. According to some embodiments, thelarge surface of impact is advantageous in achieving high durability ofthe burr, as the impact with the tissue is dispersed over a large areaon the burr. According to some embodiments, the large surface of impactwith the tissue may facilitate effective operation of tissue cutting byreduction of operation time.

When operating the cutting tip, the rotating burr impacts the targettissue, causing undesired movements of the burr which may reduce theeffectiveness of the cutting operation, as well as damage the tip.According to some embodiments, the tip includes a bearing, configured tosupport the burr bit in a desired position relative to the tip, whilefacilitating low friction rotation movement of the burr tip foroperation.

According to some embodiments, there are provided methods, systems anddevices such as medical/surgical tools/instruments, for removing tissuefrom a body. According to some embodiments, the instruments areconfigured to perform minimally invasive tissue resection, cutting,grinding and/or drilling. In an exemplary embodiment, the methods anddevices of the invention are configured to facilitate removal of hardtissue from target locations/sites adjacent vertebrae and/or siteswithin/near the spinal canal.

According to some embodiments, the instruments are configured to performprocedures such as osteophyte removal from sites underneath vertebrae,or removing soft tissue, such as a vertebra disc tissue. According tosome embodiments, the instruments are configured to operate proceduresincluding removal of osteophytes in spinal stenosis, removal ofosteophytes in cervical spinal stenosis, and spinal decompression.

In conditions involving narrowing of the spinal canal at the level ofthe neck, such as Cervical Spinal Stenosis, common treatment includes acorpectomy procedure in which a vertebra and excess bone tissue isremoved, associated with pain and long recuperation. Advantageously,devices and instruments provided herein, according to some embodiments,are configured to facilitate minimal invasive procedures of treatingcervical spinal stenosis without removal of vertebrae. According to someembodiments, the instruments are configured for safe insertion betweentwo adjacent vertebrae, allowing removal of excess osteophytes.According to some embodiments, the device/instrument is configured foruse in operations that include removal of soft tissue such as a discaltissue, allowing treating a herniated or bulged disc. According to someembodiments, the device/instrument is configured for use in operationsthat include preparation of vertebras walls for fusion.

According to some embodiments, the devices are configured for cuttingtissue, such as disc tissue, by inserting the device to the targetlocation and introducing/contacting the burr/cutting bit with the tissueto be cut. Advantageously, the device, according to some embodiments,may enable conducting procedures, such as disc removal, without therequirement of removing pieces of bone (such as the lamina) from theaffected vertebra, thus allowing minimally invasive procedures fortreating a herniated disc and contributing to higher success rates andfaster recovery of the patients.

According to some embodiments, the device is inserted through the discutilizing an accessory tool or instrument such as an endoscope, acannulated instrument configured to allow inserting the device throughthe disc without harming said disc, or similar procedures.

According to some embodiments, a surgical tissue cutting tip isintroduced, the surgical tissue cutting tip includes an elongated hollowmember, for example, a tubular member or a conduit, a burr bit and aburr shield. According to some embodiments, the elongated hollow memberhas a distal open end, and the burr tip protrudes distally from thedistal open end of the hollow member. According to some embodiments, theburr bit or cutting bit includes a proximal bit end, configured to bemechanically connected to a target end of a rotary shaft, a cylindricalburr body having circumferential cutting characteristics, and a distalbit front end.

According to some embodiments, the burr shield extends from the distalopen end of said hollow member to at least partially cover thecylindrical burr body and at least partially cover the distal bit frontend. According to some embodiments, the burr shield is integrally formedwith the hollow member at the distal open end thereof.

According to some embodiments, the burr bit is configured to rotateaxially in an axis extending from the proximal bit end to the distal bitfront end, and to affect abrasive grinding/cutting to tissue by contactwith the burr body at areas not covered/protected by the burr shield.

According to some embodiments, the bit comprises a rotary cutting blade.According to some embodiments, the bit comprises a plurality of jointedcutting elements, such as a plurality of cutting discs, and/or cuttingelements such as diamond powder

According to some embodiments, the cutting bit is cylindrical, withcircumferential cutting properties. According to some embodiments, thecutting bit is cylindrical, with radial circumferential cuttingproperties (lateral). According to some embodiments, the cutting bit iscylindrical with forward/distal circumferential cutting properties.

According to some embodiments, the cutting bit is at least partiallycoated with diamonds. According to some embodiments, the cutting bit isat least partially embedded with blades.

According to some embodiments, the tip and the cutting bit areconfigured to facilitate at least one of: lateral cutting, posteriortissue cutting, or forward cutting, based on various embodiments of theinvention.

According to some embodiments, the surgical tissue cutting tip furtherincludes a rotary shaft, configured to be placed within said elongatedhollow member, the rotary shaft includes a driving end, a target end andan elongated shaft body. According to some embodiments, the driving endis configured to be mechanically connected to a rotary motion actuator,and the a target end is positioned near the distal open end of thehollow member and configured to be mechanically connected with theproximal bit end to affect rotary motion to the burr bit, while theelongated shaft body is configured to provide/transfer rotationalmovement from a the driving end to the target end.

According to some embodiments, the device further includes a handle tofacilitate operation over the device, and a rotary motion actuator, suchas a motor for affecting a rotation movement on the shaft andconsequently on the burr bit.

Reference is now made to FIG. 1, which schematically illustrates adevice 100 for hard tissue removal, with a forward shield fordifferentiating between hard and soft tissue, according to someembodiments. According to some embodiments, device 100 includes a handle150 connected to a hollow member 130 including a cutting tip 110 forsurgical tissue cutting by the distal end thereof. According to someembodiments, the handle further includes an operational input 160utilized, for example, for providing electric energy for operating thedevice, introducing additional surgical instruments, connecting tosensors, cameras, or the like.

According to some embodiments, the diameter of the hollow member is inthe range of 2 mm to 10 mm. According to some embodiments, the overalldiameter of the hollow member is approximately 6 mm, 7 mm, 8 mm, 9 mm or10 mm. Each possibility represents a separate embodiment of theinvention. According to some embodiments, the length of the tubularmember is in the range of 100 mm to 300 mm. According to someembodiments, the length of the tubular member is in the range of 150 mmto 250 mm. According to some embodiments, the length of the tubularmember is approximately 100 mm, 150 mm, 200 mm, 250 mm or about 300 mm.Each possibility represents a separate embodiment of the invention.

According to some embodiments, the dimensions of the device/instrument,or any part thereof, are designed and shaped to facilitate a “lowprofile” safe insertion of the device in between two adjacentvertebrates and provide access to osteophytes presented underneathvertebrae.

Reference is now made to FIG. 2a , which schematically illustrates asurgical tip 200 with a forward shield 236 for differentiating betweenhard and soft tissue, according to some embodiments. According to someembodiments, surgical tip 200 includes a tubular housing such as hollowmember 230 having an open distal end 232 and protruded therefrom is aburr bit having a burr body 212, a bit front end 214 and a bit proximalend (not shown) engaged within hollow member 230. According to someembodiments, burr body 212 is cylindrically shaped with cuttingcharacteristics for achieving a large impact surface area with a targettissue intended for removal/cutting.

According to some embodiments, a burr shield extends from distal openend 232 of hollow member 230 to at least partially cover cylindricalburr body 212 by forming a lower shield 234 and at least partially coverdistal bit front end 214, forming front/forward shield 236. According tosome embodiments, the burr shield is integrally formed with hollowmember 230 at distal open end 232 thereof.

According to some embodiments, forward shield 236 is shaped forachieving separation between layers of tissue, such as soft tissue andhard tissue.

Reference is now made to FIG. 2b , which schematically illustrates across section of a surgical tip 201 with a forward shield 236,essentially as described in FIG. 2a , for differentiating between hardand soft tissue, according to some embodiments. According to someembodiments, surgical tip 201 further includes a bit support member,such as middle bearing 226 placed by a distal open end 232 supportivelysurrounding a bit proximal end 216 while facilitating rotation movementthereof. According to some embodiments, bit proximal end 216 ismechanically connected to a shaft 220 placed within hollow member 230 bya target end 222 thereof, shaft 220 being configured to induce rotationmovement on the burr bit by transfer of rotation force from a rotaryactuator, such as a motor (not shown).

According to some embodiments, middle bearing 226 is configured tomitigate undesired movement of the burr tip resulting from impact oftissue, thus, advantageously, facilitating an effective operation ofsurgical tip 201 and contribute to the durability thereof.

According to some embodiments, the connection between the bit proximalend and the shaft is facilitated by utilization of a connection tube,which in one end thereof is connected to the shaft, and in the other endthereof is connected to the bit proximal end.

According to some embodiments, the bearing is configured to support theburr/cutting bit by reducing/restricting a radial lateral movement ofthe cylindrical bit body, while allowing/facilitating an axial rotationmovement thereof on a fixed axis or a range of axis locations, andaccording to some embodiments, an axial lateral movement thereof.

According to some embodiments, the bearing may include a slide bearingplaced around part of the bit, for example near the middle of thebearing, near a proximal end thereof and/or near a distal end thereof.

According to some embodiments, the bearing may include a ball bearingplaced around part of the bit, for example near the middle of thebearing, near a proximal end thereof and/or near a distal end thereof.

According to some embodiments< the bearing may include a plain bearing,a roller bearing, or a spindle bearing.

According to some embodiments, the bearing mechanism may include asupport element, configured to reduce/restrict the radial lateralmovement of the cylindrical bit boy at least in some directions/angles,for example downward movement toward the shield.

According to some embodiments, the surgical cutting tip is configured tofacilitate a lateral axial movement of the cutting bit, that is distallyand proximally relative to the distal open end of the hollow member, forachieving cutting properties/characteristics during the cuttingoperation and or for fine tuning of the cutting location.

According to some embodiments, the axial lateral movement of the burrbit is actuated by a lateral movement actuator, such as a step-motor.According to some embodiments, the axial lateral movement of the burrbit is actuated manually by an operator controlling the extension andretraction of the shaft by a control interface on the handle of thedevice/instrument.

According to some embodiments, the elongated rotary/drive shaft isconfigured to facilitate motion actuation by means of axial rotation incombination with an axial lateral movement. According to someembodiments, the shaft is configured to transfer axial rotation forces,push forces and pull forces from an actuator to the bit. According tosome embodiments, the shaft is configured to perform as described hereinwhile being bent/curved.

According to some embodiments, the device/instrument is configured toprovide radial lateral movement of the bit and/or the tip for affectingradial lateral impact of a target tissue. According to some embodiments,the bit is laterally movable radially to facilitate a “hammering”operation.

According to some embodiments, the tubular member and the shaft areconfigured to be bendable for positioning the burr bit in desiredoperative positions for reaching the target tissue.

Reference is now made to FIG. 3a , which schematically illustrates aside view of a bent surgical tip 300 with a forward shield 336 fordifferentiating between hard and soft tissue, according to someembodiments. According to some embodiments, surgical tip 300 includes ahollow member 330 for inserting the burr bit (including a cylindricalburr body 312 and a burr front end 314) to the vicinity of a targettissue. According to some embodiments, the burr bit protrudes from adistal open end 332 of hollow member 330, and is protected by a shieldthat extends from distal open end 332 of hollow member 330 to at leastpartially cover cylindrical burr body 312 by forming a lower shield 334and at least partially cover distal bit front end 314 formingfront/forward shield 336. According to some embodiments, the burr shieldis integrally formed with hollow member 330 at distal open end 332thereof. According to some embodiments a shaft (not shown) is placedwithin hollow member 330 for inducing rotation motion on the burr bit.

According to some embodiments, hollow member 330 and shaft are bendable,for example, as illustrated, hollow member 330 is bent at a bendinglocation 331 to position the burr bit towards the target tissue forcutting/grinding operation.

According to some embodiments, bending location 331 is such that adistance between burr body 312 and bending location 331 is no largerthan 10 mm, advantageously forming a short “horizontal distance” thatcan help in reaching difficult tissue locations.

According to some embodiments, bending location 331 is such that adistance between front/forward shield 336 and a center of bendinglocation 331 is about 10-15 mm (for example, about 12-14 mm or about 13mm), advantageously helping in reaching difficult tissue locations.

Reference is now made to FIG. 3b , which schematically illustrates aperspective view of a bent surgical tip 300 as described in FIG. 3a witha forward shield for differentiating between hard and soft tissue,according to some embodiments.

According to some embodiments, the distance or length of the section ofthe hollow member extending from the beginning of the hollow member(handle end) until the beginning of the curved location (bending) isreferred to as “vertical length”.

According to some embodiments, the vertical length is in the range of50-300 mm. According to some embodiments, the vertical length is in therange of 100-200 mm.

According to some embodiments, the distance or length of the section ofthe hollow member extending from the beginning of the curved location(bending) until the end of the curved location (bending) is referred toas “bending length”.

According to some embodiments, the bending length is in the range of1-20 mm. According to some embodiments, the bending length is in therange of 3-10 mm. According to some embodiments, the bending length isapproximately 8 mm.

According to some embodiments the bending angle is in the range of 0-160degrees. According to some embodiments the bending angle is in the rangeof 30-140 degrees. According to some embodiments the bending angle is inthe range of 70-120 degrees.

According to some embodiments, the bending radius is in the range of2-12 mm. According to some embodiments, the bending radius is in therange of 6-10 mm. According to some embodiments, the bending radius isapproximately 9 mm.

According to some embodiments, the distance or length of the section ofthe hollow member extending from the end of the curved location(bending) until the cutting bit or burr bit is referred to as“horizontal length”.

According to some embodiments, the horizontal length is in the range of1-15 mm.

According to some embodiments, the hollow member is tubular, having acircular or oval cross section. According to some embodiments, thehollow member has a Euclidian shape. According to some embodiments, thecross section area of the hollow member may be constant along thelongitude thereof, or alternatively, it may vary.

According to some embodiments, the hollow member, shaft body, cuttingtip and/or cutting bit may be fabricated from common materials used insurgical devices, including, for example, stainless-steel, cobaltchrome, Nickel Titanium alloy (Nitinol), titanium, a polymer, and thelike. According to some embodiments, various device components may befabricated using common approaches such as casting, extrusion,machining, 3D metal printing and the like. According to someembodiments, the elongated shaft body and cutting tip are fabricatedfrom stainless steel.

During operation, the shaft is exposed to strains and forces that canimpact the physical properties thereof, and damage it. The parametersthat may affect the strains that the shaft is subjected to include: thebending angle of the shaft and hollow member, the rotation speed of theshaft and the burr bit, the bending radius, the length of the tip andburr bit, and the diameter of the tip and burr bit.

According to some embodiments, there is introduced a method forquantifying the quality of the shaft.

According to some embodiments, the quality of the shaft may be assessedas follows:

$E = \frac{{Bending\_ angle}*{Rotation\_ speed}}{{Bending\_ radius}*{Tip\_ length}*{Tip\_ diameter}}$

According to some embodiments, there are introduced shafts having thefollowing physical properties:

Bending angle: 30-90 deg

Rotation speed: 15,000-60,000 rpm

Bending radius: 4.5-9 mm

Tip diameter: 1.5 mm-3 mm

Tip length: 7-19 mm (for example, 9-15 mm, 12-14 mm or about 13 mm)

According to some embodiments, there are introduced shafts having thefollowing physical properties:

Bending angle: 0-90 deg

Rotation speed: 10,000-80,000 rpm

Bending radius: 2-18 mm

Tip diameter: 1-7 mm

Tip length: 1-20 mm

According to some embodiments, there are introduced shafts having thefollowing physical properties:

Bending angle: 50-80 deg

Rotation speed: 45,000-55,000 rpm

Bending radius: 6-7 mm

Tip diameter: 3-5 mm

Tip length: 19-30 mm

According to some embodiments, the cutting bit (cutter) may befabricated from, for example, 17.4 pH (thermal-hardened) stainless-steelor stainless steel 420; for example, 2.5 mm Outer Diameter with, forexample, 2-4 spiral flutes (lead angle, for example, 26 Deg, depth, forexample, 0.75 mm, width, for example, 0.8 mm) each having a sharp edgeforming a blade. According to some embodiments, the cutting bit is in ashape of a disc comprising cutting edges at its perimeter. According tosome embodiments, the cutter (cutting bit) comprises two oppositelongitudinal straight edges and two opposite lateral cutting edges.According to some embodiments, the length of the cutter portion may varydepending on use from 1 mm-100 mm (e.g. 2 mm).

According to some embodiments, the shaft (rotary shaft) includes abendable stranded wire, wherein the stranding configuration is designedfor withstanding the operation conditions according to the introducedshaft quality assessment method.

According to some embodiments, the shaft may include a substantiallyrigid portion connected to (mechanically, via crimping, or via welding),or contiguous with a substantially flexible portion. According to someembodiments, the rigid portion optionally traverses at least some of thestraight portion of the elongated hollow member, while the flexibleportion traverses the curved portion or the bending location, andoptionally some of the straight portion/sections. According to someembodiments, the shaft may include a rigid tube crimped over an end of aflexible multi-layer cable.

According to some embodiments, the multi-layer wire cable may beconfigured for high torsional rigidity and low bending rigidity,potentially enabling the wire cable to rotate at high speed while bent,potentially at a small radius of curvature. According to someembodiments, the high torsional rigidity and low bending rigidity isbeneficial for service in a bent form. Advantageously, having a lowbending rigidity may provide low bending-related stress and betterresistance to fatigue potentially caused by high rotation speed and/orhigh rotation torque. According to some embodiments, such a wire cablemay be braided, coiled or twisted from inner layers configured formaintaining high structural integrity, and optionally low torsionalrigidity, and outer layers configured for maintaining high torsionalrigidity. According to some embodiments, the multi-layer wire cableincludes at least one inner layer, optionally more, and at least oneouter layer, optionally more. According to some embodiments, in order tofurther enhance the ability of the cable to transmit torque to thecutting head without fraying and/or buckling and/or breaking, each ofthe above layers may be configured to have mechanical properties in adirection opposite to the direction of the adjacent layer.

Advantageously, the inner layer is configured to provide torsionalrigidity properties to the shaft. According to some embodiments, thetorsional rigidity, bending and flexibility capabilities are facilitatedproviding inner structural support to the coiled wires for preventingcollapsing of the coil. According to some embodiments, the innerstructural support is configured to withstand mechanical fatigue fromaltering bending stresses.

According to some embodiments, the wire cable core may be fabricated,for example, from seven, nineteen or more 304V stainless-steel (orNickel Titanium alloy) wires (each having a diameter of, for example,0.084 mm) twisted into a rope. According to some embodiments, severallayers of coils, e.g. 3 layers, are then wound around the rope core.According to some embodiments, each successive coil may optionally bewound in the opposite direction of the coil which precedes it. Accordingto some embodiments, the inner coil (closest to rope core) includes, forexample, five wires (with a diameter of e.g. 0.12 mm each), the middlecoil includes, for example, five wires (with a diameter of e.g. 0.14 mmeach) and the outer coil includes, for example, five wires (with adiameter of e.g. 0.16 mm each).

According to some embodiments, the bit length is in the range of 13 mmto 30 mm. According to some embodiments, the bit length is in the rangeof 2 mm to 10 mm. According to some embodiments, the bit length is inthe range of 4 mm to 9 mm.

According to some embodiments, the bit diameter is in the range of 0.5mm to 8 mm. According to some embodiments, the bit diameter is in therange of 1 mm to 6 mm. According to some embodiments, the bit diameteris in the range of 1.5 mm to 5 mm. According to some embodiments, thebit diameter is in the range of 2 mm to 4 mm.

According to some embodiments, the cross section area of the hollowmember is 10-100% greater than the cross section area of the shaft.According to some embodiments, the cross section area of the hollowmember is 30-70% greater than the cross section area of the shaft.

According to some embodiments, the bit is configured to rotate axiallyat rotation speed of up to 100,000 round per minute (RPM). According tosome embodiments, the bit is configured to rotate axially at rotationspeed in the range of 5,000 RPM to 100,000 RPM. According to someembodiments, the bit is configured to rotate axially at rotation speedin the range of 10,000 RPM to 70,000 RPM. According to some embodiments,the bit is configured to rotate axially at rotation speed in the rangeof 20,000 RPM to 50,000 RPM.

According to some embodiments, the torque provided to the bit is in therange of 1-15 N*cm. According to some embodiments, the torque providedto the bit is in the range of 2-10 N*cm. According to some embodiments,the torque provided to the bit is in the range of 6-8 N*cm. According tosome embodiments, the torque values refer to dynamic torque values,specifically at the rotation speeds of the bit as provided in variousembodiments.

According to some embodiments, the torque and or rotation speed arecontrolled by the operator of the device/instrument.

According to some embodiments, the cable design is capable oftransferring rotational and longitudinal motion, that is torque androtational speed and axial force and speed, along a curved path withangles described elsewhere herein, in a manner resistant to fatigue. Itis noted, however, that such paths can be fixed, as in some embodimentswhere the curved tip may be rigid, or variable, where the tip can acceptmultiple angles or curvatures before and/or during the tissue cutting.

According to some embodiments, the wire cable described above, has adiameter of, for example, 0.3 mm to 5 mm, e.g. 1 mm or 1.5 mm or 3 mm.

According to some embodiments, the proximal end of the hollow member(shaft body) may be attached to a handle which houses a drive and,optionally, a motor, as well as electrical circuitry. According to someembodiments, the handle may be configured for allowing a user tomanipulate the device and operate the motor driven cutting head. In thatrespect, the handle may be shaped substantially as an inverted cone witha length of, for example, 75-105 mm and a proximal diameter of, forexample, 20-30 mm and a distal diameter of, for example, 5-15 mm.According to some embodiments, the handle may be fabricated as a shellcomposed of one or more cast, machined or injection-molded pieces.According to some embodiments, the handle may include a user interfacefor operating the motor, setting motor parameters (for example, therotation speed and direction of rotation, etc.), setting cutting time,operating and setting irrigation and/or suction parameters, as well ascontrolling adjunct devices such as a neuro-stimulation device.According to some embodiments, the handle may be designed and configuredsuch that a surgeon maintains a clear line-of-site along the device,helping the surgeon to monitor progress while cutting some tissue andavoiding tissues not targeted for cutting.

According to some embodiments, the user interface may further include adisplay for displaying various parameters related to the motor or toirrigation, as well as information related to the cutting head andflexible drive shaft such as temperature, mechanical integrity, cuttinghead position and the like, and information related to adjunct device(for example electrodes for neuro-monitoring) used during a procedure.

According to some embodiments, the forward shield may be utilized forseparating soft tissue, such as ligaments, from hard tissue, such asbone tissue intended for cutting.

Reference is now made to FIG. 4a-f , which schematically illustratesteps of operating a surgical tip for hard tissue removal from within avertebra, according to some embodiments.

Setting 401 illustrates the insertion of the surgical tool between ahard tissue, such as bone 490 and a soft tissue such as ligament 492 byintroducing the front/forward shield 436 between bone 490 and ligament492. At this point, cutting bit 410 is approximated to come in contactwith bone 490.

Setting 402 illustrates initial drilling of the bone by operating thecutting bit 410 for drilling in bone tissue 490 to reach the depth ofapproximately the whole length of cutting bit 410 within bone 490, whileligament 492 is protected from the drilling by front shield 436, whichalso separates bone 490 from ligament 492 as the tip progresses.Generally, a major portion of the drilling activity is done by the front(distal) end of cutting bit 410.

Setting 403 illustrates further progression in drilling bone 490 in acombined resection and drilling motion.

Setting 404 illustrates tilting the tip and cutting bit 410 upwardlytowards bone 490, thereby utilizing the cuttingproperties/characteristics of the cylindrical cutting bit 410 body.

Setting 405 illustrates advancing cutting bit 410 for progressing indrilling bone 490 utilizing the cutting properties/characteristics ofthe cylindrical cutting bit 410 body.

Setting 406 illustrates removal of the tip when a desired cavity 498 isreached/achieved.

According some embodiments, there is provided a method of cutting tissueusing a device/instrument or tip as described in various embodimentsherein. The method includes, positioning the cutter of said deviceagainst tissue, and operating the device to cut the tissue. According tosome embodiments, the method is applied for treating an orthopedicindication associated with excess tissue growth. According to someembodiments, the indication is selected from the group consisting of:herniated disc, bulged disc, spinal stenosis. According to yet anotherembodiment, the spinal stenosis is cervical spinal stenosis. Accordingto some embodiments, the tissue is a bone tissue or an intervertebraldisc tissue. According to some embodiments, the method is applied forperforming at least one of the procedures selected from the groupconsisting of: corpectomy, laminotomy, laminectomy, foraminotomy,discectomy, and facetectomy. According to yet another embodiment, theprocedure is a corpoectomy. According to some embodiments, the procedureis a discectomy.

According to some embodiments, there is provided a method for treating acervical orthopedic indication associated with excess tissue growth in asubject. According to some embodiments, the method includes:

-   -   i) inserting a cutting device when the patient is in an anterior        position in between two adjacent vertebrae and through the        intervertebral disc;    -   ii) placing said device at the bottom or underneath the        vertebrae and lateral and backward cutting excess tissue,        thereby treating a cervical orthopedic indication.

According to some embodiments, the cervical orthopedic indication isselected from a group including: cervical spinal stenosis, herniateddisc, and bulged disc. According to some embodiments, the cervicalorthopedic indication is cervical spinal stenosis. According to someembodiments, the tissue is an intervertebral disc tissue or bone tissue.According to some embodiments, the method further includes a step ofcreating an incision and inserting said device through the incision.

According to some embodiments, the whole device/instrument isdisposable. According to some embodiments, parts of thedevice/instruments are disposable. According to some embodiments, thetip is disposable. According to some embodiments, the cutting bit isdisposable. According to some embodiments, the shaft is disposable.

According to some embodiments, the front distal end of the cutting bitis supported by the front shield while allowing rotation thereof.Advantageously, providing frontal support to the cutting bit may reduceundesired (non-axial rotation or movement, such as lateral movement) ofthe cutting bit and by that contribute to the efficiency and accuracy ofthe cutting operation, as well as contribute to the durability of theequipment by reducing unnecessary strain on the shaft.

According to some embodiments, at least a part of the distal front endof the cutting bit is mounted in a void/pocket within the front shield,configured to provide a low friction support for the cutting bit,allowing axial rotation while reducing lateral movement of the cuttingbit.

Reference is now made to FIG. 5a , which schematically illustrates asurgical tip 500 with a distal/front bearing (not shown) and a middlebearing 526, according to some embodiments. According to someembodiments, surgical tip 500 includes a tubular hollow member 530having a distal open end 532 with a cutting bit having a cylindricalburr body 512 and a bit front end 514 protruded from distal open end 532and a burr proximal end 516 engaged within hollow member 530 andmechanically connected to a rotary shaft 520 therein. According to someembodiments, a lower shield 534 and a forward shield 536 are extendedfrom the open end 532 of hollow member 530 to form a bottom and forwardprotection from the cutting element or cutting bit.

According to some embodiments, the cutting bit is supported by middlebearing 526 positioned around burr proximal end 516 by open end 532 ofhollow member 530. According to some embodiments, at least part of bitfront end 514 is engaged within a void in front shield 536 for providinga front support or front bearing to the cutting bit.

Reference is now made to FIG. 5b , which schematically illustrates across section of a surgical tip 501 essentially as described in FIG. 5a500 with a distal/front bearing 528 and a middle bearing 526, accordingto some embodiments. According to some embodiments, anextension/protrusion of bit front end 514 is engaged in an opening/voidin front shield 536 to form front bearing 528 for supporting the cuttingbit by allowing/facilitating axial rotation thereof and reducing lateralmovement or other non-axial rotation.

According to some embodiments, the support of the cutting tool by thefront shield may be achieved by introducing a bearing element in thefront shield, configured to surround and support at least part of thedistal front tip of the cutting bit. According to some embodiments, thesupport of the cutting bit by the front shield may be achieved bycreating a low friction contact point/area between the distal end of thecutting tip and the front shield.

Reference is now made to FIG. 6, which schematically illustrates a crosssection of a surgical tip 600 with a distal/front bearing 628, accordingto some embodiments. According to some embodiments, surgical tip 600includes a cutting bit having a burr body 612 and a bit front end 614,in addition to a shield including a lower/bottom shield 634 and a frontshield 636. According to some embodiments, at least a point orcircumferential area of front end 416 is introduced to front shield 636forming front bearing 628 point/area for providing support to thecutting bit by preventing lateral downward movement thereof whilepermitting axial rotation of the cutting bit.

According to some embodiments, the surgical tip is configured to have atleast two operation modes, one of which being an insertion mode (ornon-active state), and the other being an operation/cutting mode (oractive state). According to some embodiments, in the insertion mode, thecutting bit is positioned to not protrude upward beyond the front shieldto lower the risk of impacting tissues while inserting the tip forreaching the operation/cutting target area.

According to some embodiments, the burr/cutting/drilling bit does nothave a full rotational circular symmetry. According to some embodiments,the burr body is configured to have a short diameter angle and a longdiameter angle. According to some embodiments, the burr body iselongated perpendicularly to the axis of rotation.

According to some embodiments, in the non-active state, the cutter orcutting bit of the instrument is positioned such that its cutting edgesor segments are not exposed from any side of the device and arecovered/protected by the shields, thus allowing safe entry/insertion inbetween or through a body tissue. According to some embodiments, uponoperating the device, the cutter rotates axially and thereby extendsbeyond the shields for removing or drilling tissue in the target areas.According to some embodiments, the device comprises at least one shieldfor protecting undesirable tissue removal, such as the dural sack. Thus,the device/tool may be configured such that it enables entry into bodytissues or cavities of constrained sites without harming the surroundingtissue or at least mitigating the harm to surrounding tissue.

Reference is now made to FIG. 7, which schematically illustrates asurgical device 700 with a handle 750, a straight hollow member 730 anda tip 710 with a cutting bit 712, according to some embodiments.According to some embodiments, surgical device 700 is configured tofacilitate a non-active operation state, during which the cutting bit isminimally exposed or non-exposed to affecting cutting or impactingsurrounding tissue, and an active state, in which the cutting bit isextended to reach target tissue for cutting. According to someembodiments, surgical device 700 further includes an operational port760 for providing operational functionality such as suction of bodilyfluids, suction of ground bone tissue, insertion of further surgicalequipment, providing electric power for the operation of surgical device700, and the like.

Reference is now made to FIG. 8, which schematically illustrates a crosssection of a surgical device 800 with a handle 850, a straight hollowmember 830 and a tip 810 with a cutting bit 812, according to someembodiments, essentially similar to surgical device 700 of FIG. 7. Asillustrated, a rotary shaft 820 is placed within hollow member 830 forproviding rotation movement to cutting bit 812 from a rotary actuatorsuch as motor 852.

Reference is now made to FIG. 9a , which schematically illustrates atissue cutting tip 900 with a burr bit 912 at a collapsed/retractedposition for facilitating a non-active state for insertion of tip 900,according to some embodiments. According to some embodiments, in thenon-active state, burr bit 912 is positioned to be frontally/distallycovered by a front shield 936 and burr bit 912 with the proximal bit end916 protected/covered by lower shield 934 extended from the open end 932of a hollow member 930.

Reference is now made to FIG. 9b , which schematically illustrates atissue cutting tip 901 with a burr bit 912 at an engaged/extendedposition for facilitating an active state for insertion of tip 901,according to some embodiments. Tip 901 is essentially similar to tip 900of FIG. 9a . According to some embodiments, burr bit 912 in the activemode is axially rotated for performing cutting, and during rotation,burr bit 912 extends beyond front shield 936 for reaching target tissuesand performing cutting/grinding.

According to some embodiments, the maximal protrusion of the burr bitbeyond the front shield in the active state is in the range of 0.1 mm to4 mm. According to some embodiments, the maximal protrusion of the burrbit beyond the front shield in the active state is in the range of 0.5mm to 2 mm. According to some embodiments, the maximal protrusion of theburr bit beyond the front shield in the active state is in the range of1 mm to 1.5 mm. According to some embodiments, the maximal protrusion ofthe burr bit beyond the front shield in the active state isapproximately 1 mm.

According to some embodiments, the forward shield is circular orsemi-circular or dome shaped, with a diameter in the range of 3 mm to 10mm. According to some embodiments, the forward shield is circular orsemi-circular or dome shaped, with a diameter in the range of 4 mm to 8mm. According to some embodiments, the forward shield is circular orsemi-circular or dome shaped, with a diameter in the range of 5 mm to 7mm. According to some embodiments, the forward shield is circular orsemi-circular or dome shaped, with a diameter of approximately 6 mm.

Reference is now made to FIG. 10a , which schematically illustrates atissue cutting tip 1000 at an area of a target tissue 1096, according tosome embodiments. According to some embodiments, tip 1000 is inserted,using hollow member 1030 between two non-target tissues 1090 and 1092 ina non-active state, to reach target tissue 1096, and then change theoperation mode to an active state, in which cutting bit 1012 is rotatedaxially and extends from shield 1034 to reach target tissue 1096 forcutting, while shield 1034 also protects surrounding tissues fromcutting, such as ligament 1094.

Reference is now made to FIG. 10b , which schematically illustrates atissue cutting tip 1000 at an area of a target tissue 1096, according tosome embodiments, showing in more detail cutting bit 1012 reachingtarget tissue 1096 while front shield 1036 protects ligament 1094 fromimpact with cutting bit 1012.

Reference is now made to FIG. 11a , which schematically illustrates atissue cutting device 1100 with a hollow member 1130 and a cutting bit1112 at an area of a target tissue 1196, according to some embodiments.According to some embodiments, hollow member 1130 and encompassed shaft(not shown) are bent at a bending location 1131 on the longitude ofhollow member 1130 to position cutting bit 1112 in the area of targettissue 1196. According to some embodiments, hollow member 1130 isdivided to a “vertical length” which is the section extending from adevice handle 1150 and bending location 1131, and a “horizontal length”which is the section extending from bending location 1131 to cutting bit1112. According to some embodiments, hollow member 1130 is configured tobe inserted between tissues 1190 and 1192 to reach with cutting bit 1112to target tissue 1196 while avoiding damage to surrounding tissues 1190and 1192 and ligament 1194 by utilizing the operation modes as describedabove, and by utilization of protective shield 1134.

Reference is now made to FIG. 11b , which schematically illustrates anenlarged view 1101 of a tissue cutting device similar to tip 1100 ofFIG. 11a , according to some embodiments.

Reference is now made to FIG. 12a , FIG. 12b and FIG. 12c , whichschematically illustrate a tissue cutting tip 1200 in a tilted frontview, a side view and a perspective view respectively, according to someembodiments. According to some embodiments, tissue cutting tip 1200includes a hollow member 1230 with a distal open end 1232 and a shieldextended therefrom, forming a lower shield 1234 and a forward shield1236. According to some embodiments, a cutting bit, including a cuttingbit body 1212 and a proximal bit end 1216, is protruded from distal openend 1232. According to some embodiments, cutting body 1212 iscylindrical with cutting characteristics at the cylinder radialcircumference thereof, and configured to rotate on the cylinder axis toprovide tissue cutting capabilities.

According to some embodiments, front shield 1236 is configured to fullycover the front surface or front distal end of cutting body 1212 toprevent frontal cutting and facilitate lateral cutting.

Reference is now made to FIG. 13, which schematically illustrates atechnical design of a tissue cutting tip 1300, according to someembodiments. According to some embodiments, tissue cutting tip 1300includes a hollow member 1330 with a distal open end 1332 and a shieldextended therefrom, forming a lower shield 1334 and a forward shield1336. According to some embodiments, a cutting bit is protruded fromdistal open end 1332, the cutting bit having a proximal bit end (notshown) and a burr/cutting body 1312. According to some embodiments,cutting body 1312 is cylindrical with cutting characteristics at thecylinder radial circumference thereof, and configured to rotate on thecylinder axis to provide tissue cutting capabilities.

Reference is now made to FIG. 14, which schematically illustrates atissue cutting device 1400 with an elongated burr bit 1412, according tosome embodiments. According to some embodiments, tissue cutting device1400 includes a handle 1450 with a hollow member 1430 extended therefromand a device tip 1410, at the distal end of hollow member 1430,including cylindrical and elongated burr bit 1412 partially covered by ashield 1436. According to some embodiments, hollow member 1430 andencompassed shaft (not shown) are bent or configured to be bent at abending location 1431, to position elongated burr bit 1412 in proximityof a target tissue for cutting.

According to some embodiments, elongated burr bit 1431 is configured toperform abrasive cutting across the depth of a target tissue. Accordingto some embodiments, the length of elongated burr bit 1431 is greaterthan the depth of the target tissue.

Reference is now made to FIG. 15a , which schematically illustrates atissue cutting tip 1500 with a cylindrical elongated burr bit 1512,according to some embodiments. According to some embodiments, elongatedburr bit 1512 is protruded from an open end 1532 of a hollow member 1530bent at a bending location 1531. According to some embodiments, a shieldis extended from open end 1532 forming a side shield 1534 and a forwardshield 1536. According to some embodiments, forward shield 1536 isconfigured to separate a target tissue intended for cutting from asurrounding tissue not intended for cutting.

Reference is now made to FIG. 15b , which schematically illustrates across section of tissue cutting tip 1500 as described in FIG. 5a ,according to some embodiments. Further illustrated herein is a bentshaft 1520 encompassed within hollow member 1530 and mechanicallyconnected to burr bit 1512 for affecting an axial rotation movementthereof.

Reference is now made to FIG. 16, which schematically illustrates atissue cutting tip 1600 with a cylindrical elongated burr bit 1612,according to some embodiments. According to some embodiments, tissuecutting tip 1630 includes a hollow member 1630 bent at a bendinglocation 1631 for positioning elongated burr bit 1612 in proximity totarget tissue 1694 for affecting an abrasive cutting thereof, whileprotecting surrounding tissues, such as ligament 1696.

According to some embodiments, components and features of thedevice/instrument or parts thereof include:

-   -   an irrigation system for irrigating the tissue while        drilling/cutting, which is advantageous in preventing        overheating of the target tissue or surrounding tissues.    -   A handle for holding and operating the device.    -   A suction pump for removing tissue grinds and/or fluids from the        cutting site.

As used herein, the terms “tissue removal”, “tissue cutting”, “tissuegrinding”. “abrasive tissue cutting/grinding” may be interchangeable andinclude tissue reshaping, removal of excess tissue and/or tissuesharpening, or the like.

As used herein, the terms “bit”, “burr bit” and “cutting bit” arereplaceable, and refer to a rotatable cutting element protruding fromthe open end of the hollow member, and configured to come in contactwith a target tissue for affecting cutting thereof.

As used herein, the term “tip” refers to the engaging portion of thesurgical instrument, including the bit, at least some distal parts ofthe hollow member, the shaft or at least a distal section thereof and ashield. According to some embodiments, the term tip includes only theburr, the shield and a portion of the hollow member surrounding theproximal bit end. According to some embodiments, the term tip refers toa section of the instrument extending from the bending section of thehollow member (for example, from a center point of the bending section)to the distal front and of the bit and the shield. According to someembodiments, the tip length may be 10-16 mm, for example, about 13.03mm. According to some embodiments, the term tip may refer to a part ofthe surgical instrument configured to be inserted between bone tissue.According to some embodiments, the term tip refers to the surgicalinstrument excluding the handle, that is the hollow member, the shaft,the bit and the shield. According to some embodiments, the tip isconfigured to be stationary during operation, at least with regards toaxial rotation.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting. As used herein, thesingular forms “a”, “an” and “the” are intended to include the pluralforms as well, unless the context clearly indicates otherwise. It willbe further understood that the terms “comprises” or “comprising,” whenused in this specification, specify the presence of stated features,integers, steps, operations, elements, or components, but do notpreclude or rule out the presence or addition of one or more otherfeatures, integers, steps, operations, elements, components, or groupsthereof.

While a number of exemplary aspects and embodiments have been discussedabove, those of skill in the art will recognize certain modifications,additions and sub-combinations thereof. It is therefore intended thatthe following appended claims and claims hereafter introduced beinterpreted to include all such modifications, additions andsub-combinations as are within their true spirit and scope.

The invention claimed is:
 1. A surgical tissue cutting tool, comprising:an elongated hollow member, having a distal open end, wherein saidelongated hollow member is bent at a bending location; a burr bitconfigured for forward and lateral cutting of tissue, distallyprotruding from the distal open end of said hollow member, the burr bitcomprising: a proximal bit end, a cylindrical burr body havingcircumferential cutting/abrasive characteristics, and a close-endeddistal bit front end; a non-hollow rotary shaft comprising a driving endconfigured to be connected to a rotary motion actuator; and a targetend, mechanically connected to the proximal bit end of the burr bit, andconfigured to affect rotary motion thereto; a burr shield extending fromthe distal open end of said hollow member to at least partially coverthe cylindrical burr body, wherein a distance between said burr tip andthe bending location is less than 20 mm; and a bearing surrounding theproximal end of the burr bit, while facilitating movement thereof;wherein said burr bit is configured to rotate axially in an axisextending from said proximal bit end to said distal bit front end, andto affect abrasive grinding/cutting of tissue by contact with said burrbody at areas not covered by said burr shield; and wherein said bearingis configured to maintain the burr bit in an eccentric position relativeto said elongated hollow member and to mitigate movement of said burrbit as a result of impact with the tissue, when in use.
 2. The tool ofclaim 1, wherein said burr shield is configured to facilitate separationbetween a hard tissue intended for cutting and a soft tissue.
 3. Thetool of claim 1, further comprising a distal bearing element, integratedin said burr shield in proximity to said distal bit front end,configured to facilitate rotation of said burr bit.
 4. The tool of claim1, wherein said burr bit has a length to radius ratio in the range of0.5-2.
 5. The tool of claim 1, wherein said burr bit has a length ofabout 2-10 mm.
 6. The tool of claim 1, wherein said rotary shaftcomprises bendable coiled and stranded wires.
 7. The tool of claim 1,wherein a distance between said burr shield and a center of said bendinglocation is about 10-15 mm.
 8. The tool of claim 1, wherein a distancebetween said bending location and said burr bit is less than 10 mm. 9.The tool of claim 1, wherein the said hollow member is bent at a bendingangle of up to 90 degrees and at a bending radius of less than 10 mm atthe bending location.
 10. The tool of claim 1, further comprising ahandle configured to facilitate operation and control of said device byan operator and a rotary actuator, placed within said handle configuredto induce rotation motion to said rotary shaft by said driving endthereof.
 11. The tool of claim 1, further comprising a control-interfaceconfigured to facilitate operation control over a rotation speed of saidrotary actuator, rotation intermittency, a rotation direction or bendingof said hollow member.
 12. The tool of claim 1, wherein the proximal endof the burr bit is closer to a wall of the hollow member at a sidethereof opposite said burr shield.
 13. The tool of claim 1, wherein theburr body opposite the burr shield is essentially collinear with a wallof the hollow member.
 14. The tool of claim 1, wherein said distal bitfront end comprises a cutting edge.
 15. The tool of claim 1, whereinsaid burr bit body is devoid of a central channel extendingtherethrough.
 16. The tool of claim 1, wherein said burr shield isintegrally formed with said elongated hollow member.